Extension-trestle



(No Model.) H. H. CHILDERS.

A EXTENSION TRESTLB. No. 315,726. Patented Apr., 14, 1885.

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HENRY H. oniLDEss, or LOUISVILLE, KENrUoKY.

EXTENSION-TRESTLE.l

SPECIFICATION forming part of Letters Patent No. 315,726, dated April 14:, 1885.

Application tiled November 2, 1883. (No model.)

To @ZZ whom it may concern,.-

Beit known that I, HENRY H. CHiLDERs, a citizen oftheUnited States, residing at Louisville, in the county of Jefferson and State of Kentucky, have invented a new and useful Improvement in Extension-Trestles, of which the following is a description.

This invention relates to that class of trestles which are used, in connection with sawbcnches, inortising-machines, &o., to support thatV portion of long timbers, plank, &c.,whioh extends beyond the table on which they are being worked; and its object is to provide means whereby a trestle may be readily ad- 15 justed to the height required to support that portion of any work which projects beyond the bench, means whereby the same may be quickly lowered out of the way by the operators foot when no longer required, leaving the hands of the operator free for other purposes, and means whereby the device shall be protected from injury in the severe use to which it is liable.

To this end my invention consists in the coni struction and combination oi' parts forming an adj ust-able trestle, hereinafter described and claimed, reference being had to the accompanying drawings, in which- Figure l is a central longitudinal vertical section of my trestle, and Fig. 2 is an end View thereof, partly broken away to show the interior.

The standards L, the table K, the sills M and J, and thebraccs I are rigidly secured together and form the frame oi' the machine.

C C are vertical boxes secured on the outer faces of the standards L and serving as guideways for the slides B.

A is a roller journaled in bearings on top of the slides B, upon which timbers and other heavy work may be rolled to a saw-bench.

D represents two racks secured on the inner faces of the slides B between the slides and the standards L, so that they are protected from gathering shavings, chips, &c., and the teeth of these racks face downward to further prevent any accumulation of dirt in them.

.E represents pawls pivoted in a fixed portion of the frame, either the table K or the standards L, to engage with their upper ends the racks D, for the purpose of holding the roller A, which is the active or workbearing G is a contractible spring acting between the lower ends of the pawls to draw them together, thereby forcingthe upper ends into engagement with the racks. The racks and the roller may be raised by taking hold of the roller; but when raised they cannot be depressed until the pawls are disengaged.

F represents a pair of trip-links pivoted together centrally, and pivoted at their ends to the pawls E. Their weight acts in the same direction as the spring-that is, to hold the pawls engaged with the racks. In practice the central joint of these links hangs less than two feet above the ground, so that when it is desired to lower the roller the operator has only to raise the center of the links to disengage the pawls, leaving the slides B free to drop to the bottom.

H represents a pair oi' springs or cushions located at the bottoni of the boxes C in the paths of the slides B to receive them when they fall, to prevent damage to the machine.

In managing heavy timbers, with which this trestle is mostly required, both hands of the operator are needed. I have therefore located the trip-links F where they may be easily kicked upward by a foot of the operator while his hands are otherwise occupied.

That I claim as my invention, and desire to secure by Letters Patent, is

l. The combination of the frame, including the standards L, the boxes C, secured on the outer faces of the said standards, the springpau-ls E, pivoted in the frame, the slides B,

fitted within the bores, the racks D, fixed to' the slides, having downward-facing teeth in position to be engaged by the pawls E, and the roller A, journaled on top of the slides B, substantially as shown and described.

2. The combination ofthe frame, including the standards L, the boxes G, secured on the outer faces thereof, the slides B, fitted into the said boxes, the roller A, journaled on top of the slides B, the racks D, secured to the slides, having downward-iacing teeth, the pawls E, pivoted near their middles in the frame to engage the racks, and the links F, pivoted at their outer ends to the lower ends of the pawls, and pivoted together midway the frame, substantially as shown and described.

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3. The combination of the frame, including bottoms of the boxes C, adapted to receive the the standards L, che boxes C, secured on the fall of the slides, substantially as shown and ro Outer faces thereof, the slides B, tted into described. the said boxes, the roller A, journaled on top 5 ofthe slides, the racks D, secured to the slides, HENRY H CHILDERS the pawls E, pivoted to the frame to engage Witnesses: the racks, the trip-links F, pivoted to the lower N. S. MAXWELL, ends of the pawls, and the cushions H in the GEO. S. MAXWELL. 

